This course develops skills in evaluating the operation of vented combustion appliances under conditions which may not allow them to function properly. Students will learn the importance of conducting a Daily Safety Test Out / Worst Case Draft Test; set-up procedures for pressure testing the combustion appliance zone; how to determine the worst-case configuration; draft test procedures for water heaters and furnaces; minimum draft testing requirements; and permanent corrective solutions that will minimize back-drafting and carbon monoxide poisoning.